The Plan Your Own Party Kit is a kit for throwing fun parties that appears in the episode "Party Pooper Pants."
Inside the kit contains a list of Bikini Bottomites to invite to the party, an instruction manual, and some party supplies (balloons, noise makers, etc.)
Barg'N-Mart sells these kits in a party-themed box which is turquoise on the front side and yellow on the middle, both of which depict colorful balloons and streamers. The boxes their sold in at the store also contain a white "sale tag" on the front and a red shell with streamers on the back as well as yellow, blue, and green balloons on said shell.
Role in the episode
SpongeBob is planning a special house party for the night and needs the best ideas on how to host it. As a result, he stops by Barg'N-Mart to buy a Plan Your Own Party Kit, which the storekeeper, Lou, offers him for free if SpongeBob promises to leave the store and get out of his hair, which he does.
Afterwards, taking the advice the kit offers him, SpongeBob expects the party to be a blast. Unfortunately, it isn't (at least not for him), as the guests aren't following the routine of activities in order.
When Officer John Slugfish and Nancy catch SpongeBob in a bunny outfit, attempting to break into his own house after being locked out as a result of the guests' antics, the two policefish accuse him of attempted burglary. However, SpongeBob informs them that he lives there and that he's throwing a party, which leads the two cops to asking why they weren't invited. SpongeBob tells them that the Plan Your Own Party Kit didn't mention the police, getting him arrested and forced to stay behind bars for the night.